After 4 Months In Maintenance NASA’s SOFIA 747 Returns To The Sky

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) has been notably absent from US skies for several months now. The Boeing 747SP-based flying telescope has been in maintenance in Hamburg, Germany, since last September. However, she is now almost ready to fly once more but plans to stay in Europe for a little while longer.

SOFIA is almost ready to depart Hamburg, but not for the USA. Photo: NASA

Four months of maintenance

If you didn’t already know, NASA operates a rare Boeing 747SP as a stratospheric observatory. Named SOFIA, for the Stratospheric Observatory for Infrared Astronomy, this aircraft is the only airborne observatory in the world. When combined with an increasingly rare airframe and the copious amounts of laboratory equipment onboard, SOFIA is one of the most valuable aircraft on the planet.

The NASA flying telescope arrived in Hamburg on September 30th last year. It flew in from Palmdale, California, where it spends most of its life, operating out of NASA’s Armstrong Flight Research Center at Palmdale Regional Airport. The Boeing 747 typically flies from PMD for around eight hours, heading up to around 40,000 feet to get uninterrupted views of the cosmos.

SOFIA Is the world’s only airborne observatory. Photo: NASA

According to flight data from, SOFIA has operated 42 flights in the last 12 months, flying for around 337 flight hours in total. Although things were a bit quiet between April and July for SOFIA, the team picked up the pace in the fall, with 13 flights operated in September alone.

After 4 Months In Maintenance NASA’s SOFIA 747 Returns To The Sky
Flight data from

However, since then, she has been in Hamburg at the Lufthansa Technik base in Hamburg, having a heavy C check. Lufthansa Technik is usually the partner of choice when it comes to maintenance for SOFIA, having completed her C check in 2014 and another heavy maintenance check in 2017. It is these technicians’ responsibility to keep this awesome bird airborne until at least 2034.

Heinz Hammes, Project Manager SOFIA, at the German Aerospace Center, commented on the choice of Lufthansa Technik, saying,

“The extensive experience with Boeing 747SP aircraft was decisive for us when we chose Lufthansa Technik as maintenance provider for SOFIA’s maintenance visit. After the checks in 2014 and 2017, we were glad to return the aircraft to the capable hands of Lufthansa Technik as we were extremely impressed with the high quality of work and expertise of their staff.”

After four months of work, she’s ready to leave Hamburg. Photo: Lufthansa Technik

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Ready to get back to work

After four months of extensive work by the team at Lufthansa Technik, SOFIA is almost ready to get back to her very special missions. However, this time, she’ll be operating out of a slightly different location.

From Thursday (February 4th), SOFIA will reposition to Cologne in Germany to conduct scientific research flights from there. Speaking at a press conference, as reported by AeroTELEGRAPH, Michael Hütwohl, Sofia Telescope Manager at the German Sofia Institute, commented,

“For the first time, we will be flying a series of missions from Cologne.”

20 flights are planned from Cologne. Photo: Lufthansa Technik

All in all, 20 flights are planned from the German city over a six week period. While this is partly about operating SOFIA from a new airport, it’s also due to travel restrictions impacting European researchers traveling back to the states. However, it will not be easy, as Hütwohl explained,

“Scientific flights over Europe are a challenge. Because you have to do with many countries, regulations and air traffic controls.”

The lack of a Single European Sky makes keeping SOFIA in Europe for any longer than is absolutely necessary an unattractive prospect. Nevertheless, if you’re a European-based spotter, be sure to look up over the coming weeks and you might catch a glimpse of this rare and unique aircraft.